A Generalized Method for the Synthesis of Carbon-Encapsulated Fe[sub.3]O[sub.4] Composites and Its Application in Water Treatment

In this paper, a simple and environmentally friendly method was developed for the preparation of highly stable C@Fe[sub.3]O[sub.4] composites with controllable morphologies using sodium alginate as the carbon source and the easily obtained α-Fe[sub.2]O[sub.3] as the precursors. The morphologies of the as-prepared C@Fe[sub.3]O[sub.4] composites, inherited from their corresponding precursors of α-Fe[sub.2]O[sub.3], survived from the annealing treatments, were characterized by the field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The C@Fe[sub.3]O[sub.4] composites resisted to oxidation, acidification and aggregation, exhibiting porous structures and ferromagnetic properties at room temperature. Moreover, the adsorption performance of the C@Fe[sub.3]O[sub.4] composites was evaluated by absorbing MB (methylene blue) in liquid environment. Experiments indicated that the C@Fe[sub.3]O[sub.4] composites exhibited highly enhanced adsorption capacities and efficiencies as compared with their corresponding precursors of α-Fe[sub.2]O[sub.3]. This generalized method for the synthesis of C@Fe[sub.3]O[sub.4] composites provides promising applications for the highly efficient removal of MB from industrial effluents.